Optimized testing to monitor biologics therapy
Many patients may have flare-ups of their disease, or they may stop responding to treatment. In these situations, the clinician may choose to increase the dose administered or recommend more frequent injections. One cause of decreased response to treatment is the appearance of anti-drug antibodies, or “immunogenicity.”
To monitor for immunogenicity, we have implemented a reflexive testing approach that aligns with American Gastroenterology Association (AGA) guidelines. This approach first measures the biologic concentration within a patient’s specimen. Then, if necessary, an additional test is performed to assess the presence of antibodies to a specific drug that the patient has been receiving. The information from these tests helps health care providers determine if their patients are experiencing a loss of response to a specific therapy. If so, clinicians can adjust treatment plans.
Benefits of our reflexive approach
Clinically significant antibodies to these drugs are found in patients with very low trough concentrations in their serum. Therefore, a reflexive approach, which performs testing only when it is clinically relevant, benefits patients and reduces costs for the ordering institution.
When do these tests reflex?
When concentration results are below a specified level, testing for antibodies to the specific drug will be performed at an additional charge.
|Adalimumab||≤ 8.0 mcg/mL|
|Infliximab||≤ 5.0 mcg/mL|
|Vedolizumab||≤ 15.0 mcg/mL|
Panel testing for newer therapies
For newer therapies that do not yet have well-established therapeutic thresholds and optimal concentrations associated with good outcomes, we offer testing that performs both quantitation and antibody testing on all specimens.
As more data is generated for these therapies, and as guidelines are updated, creation of reflex testing panels will be pursued.
Edward Loftus, M.D., talks biologic therapies
Edward Loftus Jr., M.D., a gastroenterologist at Mayo Clinic, provides an overview of our reflexive approach to optimizing treatment for inflammatory bowel disease.
Clinical action enabled by this testing
HLA-DQA1 typing to facilitate decision on mono- vs. combo-therapy decision
A recent genome-wide association study* performed in a cohort of 1,610 anti–TNF-naïve patients with Crohn’s disease found that carriers of the HLA-DQA1*05 allele had almost double the risk of immunogenicity to anti-TNF therapies.
This data, while needing additional confirmatory research, was compelling enough that it is reasonable to begin checking the HLA marker as an additional data point to guide mono- vs. combo-therapy decisions for patients who are about to begin anti-TNF therapy.
Additionally, for patients already on anti-TNF therapy with suspicion of therapeutic failure, checking the HLA marker could be another useful data point if, and when, the patient's therapy is changed.
*The Personalising Anti-TNF Therapy in Crohn’s Disease study (PANTS)
The Personalising Anti-TNF Therapy in Crohn’s Disease Study (PANTS) was a United Kingdom-wide, multicenter, prospective observational cohort reporting the treatment failure rates of the anti-TNF drugs infliximab and adalimumab in 1,610 anti–TNF-naïve patients with Crohn’s disease. The initial study with this cohort was aimed at identifying clinical and pharmacokinetic factors that predict primary non-response at week 14 after starting treatment, non-remission at week 54, and adverse events leading to drug withdrawal.
Learn more about how to order this evaluation at your institution.